Someone says to me, when I am sure that the market is going to collapse, I get rid of currencies immediately and buy them back when they decrease in order to avoid losses. For him, losses are calculated per day, meaning if he loses his job, he says it is not necessary for me to wait for it to return, but I will sell it and compensate for my loss with another currency.

On the one hand, he may be right if the market is closer to collapse than to stability and rise.

But in other cases, he will miss many opportunities and lose many profits. In the end, everyone has his own method, and with time he will become an expert and will be able to determine the appropriate method.